Abstract: In an electron gun assembly, its main convergence lens is composed of a focus electrode to which a focus voltage is applied, an anode electrode to which a high anode voltage is applied, and an intermediate electrode which is provided between the focus and anode electrodes and to which a high intermediate potential higher than the focus voltage and lower than the anode voltage is applied. The anode and intermediate electrodes are each a cylindrical unit long in the in-line direction. In the direction crossing at right angles with the in-line direction of the cylindrical units, the diameter of the opening in the anode electrode is set smaller than that of the opening in the intermediate electrode, thereby forming a multiple pole lens into a main electron lens of large aperture.

Abstract: A main lens of an electron gun assembly comprises a sixth grid, a seventh grid, an eighth grid, and a ninth grid. An asymmetric lens section is created between a fifth grid and the sixth grid on a cathode side of the main lens. The asymmetric lens section has such asymmetry that lens functions of the asymmetric lens section acting on the electron beams are different between the horizontal direction and the vertical direction, and has a lens power varying in synchronism with the deflection of the electron beams. In this asymmetric lens, the asymmetry for a center beam differs from that for side beams.

Abstract: An electric field expansion type main lens portion is constituted by including a focus electrode to which a focus voltage on a first level is applied, an anode electrode to which an anode voltage on a second level higher than the first level is applied, and two auxiliary electrodes to which a voltage on a third level higher than the first level and lower than the second level is applied and which are arranged between the focus electrode and the anode electrode. An electrode length of each of the two auxiliary electrodes along an electron beam traveling direction is constituted so as to differ in accordance with a difference in potential between electrodes arranged at front and rear positions in the electron beam traveling direction of each auxiliary electrode.

Abstract: An electron gun structure includes a first non-axial-symmetrical lens portion which is arranged in the vicinity of an electron beam formation portion, and a second non-axial-symmetrical lens portion formed to a main lens portion, the first non-axial symmetrical lens portion has a lens action in the vertical direction that a focusing action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams, and a comprehensive lens system of the second non-axial-symmetrical lens portion and the main lens portion has a lens action in the vertical direction that a divergence action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams.

Abstract: An electric field expansion type main lens portion is constituted by including a focus electrode to which a focus voltage on a first level is applied, an anode electrode to which an anode voltage on a second level higher than the first level is applied, and two auxiliary electrodes to which a voltage on a third level higher than the first level and lower than the second level is applied and which are arranged between the focus electrode and the anode electrode. An electrode length of each of the two auxiliary electrodes along an electron beam traveling direction is constituted so as to differ in accordance with a difference in potential between electrodes arranged at front and rear positions in the electron beam traveling direction of each auxiliary electrode.

Abstract: A main lens is composed of a dynamic focus electrode, a first auxiliary electrode, a second auxiliary electrode and an anode, which are successively arranged in a direction of travel of electron beams. A sub-lens provided on a cathode side of the main lens is composed of a third grid, a fourth grid and a fifth grid. The first auxiliary electrode is connected to the fourth grid, and both are connected to a voltage supply terminal on a resistor near the fourth grid. A fixed focus voltage is applied to the third grid and fifth grid sandwiching the fourth grid.

Abstract: A main lens of an electron gun assembly comprises a sixth grid, a seventh grid, an eighth grid, and a ninth grid. An asymmetric lens section is created between a fifth grid and the sixth grid on a cathode side of the main lens. The asymmetric lens section has such asymmetry that lens functions of the asymmetric lens section acting on the electron beams are different between the horizontal direction and the vertical direction, and has a lens power varying in synchronism with the deflection of the electron beams. In this asymmetric lens, the asymmetry for a center beam differs from that for side beams.